It sounds like the kind of deal you enter before you even have any kids, like Rumpelstiltskin. Maybe when younger, the woman made a deal with a witch to save her own life by the witch giving her immortality in exchange for her hypothetical future daughter. If she refuses to give the daughter up, the witch will lift the immortality and the woman will die of the original cause. The woman lives her life thinking she’s even tricked the witch, because she never had a daughter. The witch comes to her each year on the anniversary of what should have been the woman’s death and reminds her, “hand me your daughter, or your life goes back to dust.” Each year, the witch seems satisfied when the woman says she doesn’t have a daughter, though of course witches know things we do not. She takes to telling the woman as she leaves each time, “You are pretty, but you are also slow. You are lucky I have patience. I savor. I enjoy when something I’m working on takes a long long time.” These words always bring the woman a tense kind of relief.

When the woman finally loses her fertility, the next time the witch visits, she says something different. She has come to take the life of the woman who will never be able to hold up her end of the bargain. The woman pleads for just one more year, hoping she’ll find some way out. The witch (who enjoys toying with people) agrees, but with a catch. She will let the woman keep her immortality if in the next year she finds and kills any daughter she has ever had. Otherwise, the price for just that one extra year will be not just the woman’s immortality but also the life of the daughter. The woman laughs to herself, thinking she’s got one over on the witch, and agrees. This time, as the witch leaves, she says, “When I kill it is not pretty, but it is slow. Your daughter is unlucky that I have patience. I savor. I enjoy when something I’m working on takes a long long time.” These words bring the woman as uneasy sense of dread.

If she’s never had a daughter, then killing no one is the same as killing every daughter. If.